Recently Sulzer Hickham USA was presented with the difficult task from one of its very important customer’s in Colombia. The challenge was to receive two identical highpressure gas injection compressors, one having a crack in the rotor’s shaft, and one with a major impeller failure.
The repair objectives included the gathering of necessary data to perform a failure analysis on both failed components, then create one good rotor/bundle assembly with the serviceable parts from each rotor, and complete the task in less than 15 days.
The compressor bundles were received at 12:30 a.m. on June 7,2002 and immediately immersed into the repair process. Each rotor was disassembled (after resonance testing). Incoming inspection criteria and failure protocol at Sulzer Hickham USA has been developed over many years. The experience level of the personnel at both the shop level and in Engineering analysis is second to none when it comes to helping a client out of a critical situation.
The individual impellers from both rotors were again ring-tested in the disassembled condition, qualified for re-use via dimensional inspections and NDT to determine if there were enough good parts to make one reliable rotor. Once it was determined there were sufficient good parts to create one rotor, Sulzer Hickham USA co-workers were released to work their magic.
Assembly proceeded without incident. The rotor went through Sulzer Hickham USA’s “full speed balance”
and responded well. On Wednesday (afternoon), June 12, the rotor, assembled into its stationary bundle, was shipped. The client had chartered a cargo plane to expedite shipment to Colombia.
While all of the action was going on at Sulzer Hickham USA’s LaPorte, TX, plant, an engineering expert from LaPorte was on-site in Colombia, reviewing all the areas that may have contributed to the compressor casualty in the first place. Numerous actions were taken to eliminate the reoccurrence of such a problem. An impressive delivery of less than six days was achieved. The customer, which reported that his production losses were over USD 45 000 a day in crude oil, was needless to say, ecstatic.
The Aftermath
The damaged parts (the shaft and impeller) were subjected to failure analysis protocol. The results of the
analysis will be critical in preventing future problems and were used to dictate operating parameters for the
repaired rotor and will generate recommendations to be implemented into manufacturing a replacement rotor. Again, Sulzer Hickham USA performed all of the analysis and generated the reports, one for perating parameters for the repaired rotor, and one with recommendations for the new rotor, in house and in a time frame of two weeks.
Ron Shaver
Sulzer Hickham USA |